1191 



sible that their oxido-acid was a mixture of the cis- and (he 

 trans-compound). 



The change of the configuration, established by us, joins the 

 inversions so often observed when one attacks the valencies of an 

 atom, which is bearer of stereoisomerism. However, it differs thus 

 far from the known cases, that — after definitive confirmation of 

 the determination of the configuration by means of boric acid — 

 it will be certain which glycol has been formed with change of the 

 configuration. 



From the mixture of the two hydrindene diols, resulting from 

 the hydration of the oxide, it is easy to extract the one, having the 

 highest m.p., as it is much less soluble. By recrystallisation from 

 toluene or water we obtained the trans-diol, m.p. J 59, 5° — 160,5° 

 (a mixture with the diol from the diacetate showed no depression). 

 The mother-liquors furnished the more soluble glycol, accompanied 

 however by a small quantity of the isomer; these mixtures begin 

 to melt from 92° — 93° (this seems to be the eutectic temperature). 



Only after many fruitless exertions, when the cis-dibenzoate 

 turned out to be less soluble than the trans-dibenzoate, we succeeded 

 along that course in isolating the cis-dibenzoate, m.p. 108,5° — 111° 

 from the mixture and in converting it by saponification into the 

 pure cis-diol, m.p. 107° — 108,5° after sintering at 106° (no depression 

 after mixing with the diol, obtained by potassium permanganate, 

 was observed). 



During the investigation, which for the present has been com- 

 municated in part, the connection with the Walden Inversion i<t. 

 has ever been kept in view. After conclusion of the work one of 

 us hopes to lay down the results in a dissertation. 



Lah. for Organic Chemistry of the 

 Technical University 

 Delft, February 19, 1918. 



